After the buyer sends an OrderRequest to the supplier, and the order in the PunchOutOrderMessage is approved, the OrderRequest has to be correlated to the shopping session. Currently, the PunchOutOrderMessage does not have explicit fields to pass supplier session IDs back to the Ariba Buyer. Consequently, the OrderRequest does not include any supplier session ID. Ariba suggests that this information (sessionIDs) be sent from the supplier to the buyer in the SupplierAuxilaryPartID in ItemOut element(s) in the PunchOutOrderMessage. The ItemOut element(s) must be returned from the buyer to the supplier in the OrderRequest message.